Calcium and Lipid Concentrations
Source: Reid IR, et al. Effects of calcium supplementation on serum lipid concentrations in normal older women: A randomized controlled trial. Am J Med 2002;112: 343-347.
Design/Setting/Subjects: In a substudy of a larger trial assessing the effects of calcium on fracture incidence, 223 postmenopausal women (not receiving therapy for osteoporosis or hyperlipidemia) were randomized to calcium citrate (1 g/d) or placebo for one year.
Outcome Measures: Fasting serum lipid concentrations, obtained at baseline, 2, 6, and 12 months.
Results: Compared to the placebo group, high-density lipoprotein (HDL) cholesterol levels in the calcium group were significantly higher, about 7% above baseline (0.09 mmol/L, 95% confidence interval [CI] 0.02-0.17, P = 0.01). The ratio of HDL to low-density lipoprotein (LDL) also increased more in the treated group (0.05 mmol/L, 95% CI 0.02-0.08). There was no significant difference in triglyceride levels, LDL cholesterol levels, or body weight. Baseline calcium intake, fat intake, or lipid levels did not affect response to supplementation.
Funding: Health Research Council of New Zealand.
Comments: Calcium may benefit lipids as well as bone. A previous crossover study in 56 hypercholesterolemic patients treated with placebo or calcium carbonate (1.2 g/d ´ six weeks) found that in the treated group, LDL decreased by 4% and HDL cholesterol increased by 4%.1 Another study, however, found no benefit of calcium carbonate (1 g/d or 2 g/d ´ four months) over placebo on lipid parameters in 193 men and women.2
Calcium binds to fatty acids and bile acids in the gut, thus interfering with lipid absorption. As previously reported in Alternative Therapies in Women's Health (April, 2001), the addition of calcium to chocolate bars decreases fat absorption. The idea that calcium may decrease fat absorption may be a potent incentive for patients to take calcium supplements (and, perhaps, to take them with chocolate). v
1. Bell L, et al. Cholesterol-lowering effects of calcium carbonate in patients with mild to moderate hypercholesterolemia. Arch Intern Med 1992;152:2441-2444.
2. Bostick RM, et al. Relation of calcium, vitamin D, and dairy food intake to ischemic heart disease mortality among postmenopausal women. Am J Epidemiol 1999;149:151-161.